A novel electrochemical sensor based on gold nanoparticles and molecularly imprinted polymer with binary functional monomers for sensitive detection of bisphenol A

In this paper, a novel molecularly imprinted electrochemical sensor was developed for the determination of bisphenol A (BPA). Au nanoparticles (AuNPs) were modified onto the surface of a glassy carbon electrode (GCE) by electrodeposition method. BPA was used as the template molecule, while 4-aminothiophenol (4 ATP) and chitosan (CS) were used as the binary functional monomers. After 4-ATP was modified on the AuNPs by self-assembly, electropolymerization was carried out by cyclic voltammetry (CV) in the presence of CS and BPA to produce molecularly imprinted polymers (MIPs). The prepared sensor was denoted as MIPs/AuNPs/GCE. The morphologies of the electrodes were characterized by scanning electron microscopy (SEM). The MIPs were characterized by Fourier transform infrared spectroscopy (FT-IR). The electrochemical performance of the imprinted electrochemical sensor was investigated by cyclic voltammetry and electrochemical impedance analysis (EIS) techniques in detail. The experimental results showed that the gold nanoparticles could increase the conductivity of the MIPs significantly. The imprinted electrochemical sensor was successfully applied to determine BPA by linear scan voltammetry (ISV). Under the optimal condition, the oxidation peak currents of BPA exhibit a well linear relationship toward the BPA concentrations in the range from 1.5 x 10(-8) mol L-1 to 5.5 x 10(-8) mol L-1, with a detection limit of 1.1 x 10(-8) mol (S/N = 3) and a correlation coefficient of 0.9996. The sensor possesses good stability, selectivity and high sensitivity to BPA, which was successfully applied to detect BPA in actual samples such as plastic and milk. The recoveries were in the range of 97.6-106.5%. (C) 2017 Elsevier B.V. All rights reserved.